Scientists Closer to Creating Cartilage From Stem Cells

Scientists are making significant strides in creating cartilage from stem cells that one day may be used to treat osteoarthritis.

In research funded by Arthritis Research UK, professor Sue Kimber and her team in the Faculty of Life Sciences at the University of Manchester has developed a protocol under strict laboratory conditions to grow and transform embryonic stem cells into cartilage cells (also known as chondrocytes). “This work represents an important step forward in treating cartilage damage by using embryonic stem cells to form new tissue, although it’s still in its early experimental stages,” Kimber said.

The team’s research was published in Stem Cells Translational Medicine.

During the study, the team analyzed the ability of embryonic stems cells to become precursor cartilage cells. Those cells then were implanted into cartilage defects in the knee joints of rats.

After four weeks, cartilage partially was repaired and following 12 weeks a smooth surface, which appeared similar to normal cartilage, was observed. Further study of this newly regenerated cartilage showed that cartilage cells from embryonic stem cells were still present and active within the tissue.

Developing and testing this protocol in rats is the first step in generating the information needed to run a study in people with arthritis. Before this will be possible more data will need to be collected to check that this protocol is effective and that there are no toxic side-effects.

But researchers contend their study is very promising, as the protocol not only generated new, healthy-looking cartilage but perhaps more importantly, there were no signs of any side effects such as  abnormal or disorganized joint tissue or tumors. Further work will could prove the method to be a safe and effective treatment for people suffering from joint damage, the researchers claim.

Chondrocytes created from adult stem cells currently are being experimentally used but their manufacturing process is expensive because they cannot be produced in large quantities.

With their capacity to proliferate, embryonic stem cells, which can be manipulated to form almost any type of mature cell, offer the possibility of high-volume production of cartilage cells. Their use also would be cheaper and applicable to greater number of arthritis patients, the Kimber and her team note. “We’ve shown that the protocol we’ve developed has strong potential for developing large numbers of chondrogenic cells appropriate for clinical use,” she said. “These results thus mark an important step forward in supporting further development toward clinical translation.”

Osteoarthritis affects more than 8 million people in the United Kingdom, and is a major cause of disability. Worldwide estimates indicate that 9.6 percent of men and 18 percent of women aged 60 and older have symptomatic osteoarthritis, which occurs when cartilage at the ends of bones wears away causing joint pain and stiffness.

“Current treatments of osteoarthritis are restricted to relieving painful symptoms, with no effective therapies to delay or reverse cartilage degeneration. Joint replacements are successful in older patients but not young people, or athletes who’ve suffered a sports injury,” said Dr. Stephen Simpson, director of research at Arthritis Research UK. “Embryonic stem cells offer an alternative source of cartilage cells to adult stem cells, and we’re excited about the immense potential of professor Kimber’s work and the impact it could have for people with osteoarthritis.”